Optical positioning sensor

ABSTRACT

A sensor is disclosed that provides measurements in multiple degrees of freedom without significantly increasing size, complexity, or cost. The sensor can include a light component in support of a first light source operable to direct a first beam of light, and a second light source operable to direct a second beam of light. The sensor can also include an imaging device that can directly receive the first beam of light and the second beam of light and convert these into electric signals. The imaging device and the light component can be movable relative to one another. The sensor can further include a light location module and/or a position module configured to receive the electric signals and determine locations of the first beam of light, the second beam of light on the imaging device and a relative position of the imaging device and the light component.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.15/482,126, filed Apr. 7, 2017, which is a continuation of U.S. patentapplication Ser. No. 15/005,411, filed Jan. 25, 2016, which is acontinuation of U.S. patent application Ser. No. 13/937,922, filed Jul.9, 2013, now U.S. Pat. No. 9,245,916, issued Jan. 15, 2015, which isincorporated by reference as if fully set forth.

Sensors are used in a wide range of applications and are adapted tomeasure a wide variety of quantities. Many sensors can determine adesired quantity using a displacement measurement, such as a positionsensor, a strain gage, a load cell, an accelerometer, an inertialmeasurement unit, a pressure gage, etc.

BRIEF DESCRIPTION OF THE DRAWINGS

Features and advantages of the invention will be apparent from thedetailed description which follows, taken in conjunction with theaccompanying drawings, which together illustrate, by way of example,features of the invention; and, wherein:

FIG. 1 is a side schematic view of a sensor in accordance with anembodiment of the present invention.

FIG. 2 is a top schematic view of a light component of the sensor ofFIG. 1.

FIG. 3A illustrates a side schematic view of a light source of a sensorin accordance with an embodiment of the present invention.

FIG. 3B illustrates a side schematic view of a light source of a sensorin accordance with another embodiment of the present invention.

FIG. 4 is a top schematic view of the sensor of FIG. 1 undergoingrelative movement of a light component and an imaging component in twotranslational degrees of freedom, in accordance with an embodiment ofthe present invention.

FIG. 5 is a top schematic view of the sensor of FIG. 1 undergoingrelative movement of a light component and an imaging component in arotational degree of freedom, in accordance with an embodiment of thepresent invention.

FIG. 6 is a side schematic view of the sensor of FIG. 1 undergoingrelative movement of a light component and an imaging component in atranslational degree of freedom, in accordance with another embodimentof the present invention.

FIG. 7A is a side schematic view of the sensor of FIG. 1 undergoingrelative movement of a light component and an imaging component in arotational degree of freedom, in accordance with another embodiment ofthe present invention.

FIG. 7B is a side schematic view of the sensor of FIG. 1 undergoingrelative movement of a light component and an imaging component in arotational degree of freedom, in accordance with yet another embodimentof the present invention.

FIG. 8 is a top schematic view of a light component of a sensor inaccordance with another embodiment of the present invention.

FIG. 9 is a perspective schematic view of a sensor in accordance withyet another embodiment of the present invention.

FIG. 10A is a side schematic view of a sensor in accordance with yetanother embodiment of the present invention.

FIG. 10B is a side schematic view of a sensor in accordance with stillanother embodiment of the present invention.

Reference will now be made to the exemplary embodiments illustrated, andspecific language will be used herein to describe the same. It willnevertheless be understood that no limitation of the scope of theinvention is thereby intended.

DETAILED DESCRIPTION

As used herein, the term “substantially” refers to the complete ornearly complete extent or degree of an action, characteristic, property,state, structure, item, or result. For example, an object that is“substantially” enclosed would mean that the object is either completelyenclosed or nearly completely enclosed. The exact allowable degree ofdeviation from absolute completeness may in some cases depend on thespecific context. However, generally speaking the nearness of completionwill be so as to have the same overall result as if absolute and totalcompletion were obtained. The use of “substantially” is equallyapplicable when used in a negative connotation to refer to the completeor near complete lack of an action, characteristic, property, state,structure, item, or result.

As used herein, “adjacent” refers to the proximity of two structures orelements. Particularly, elements that are identified as being “adjacent”may be either abutting or connected. Such elements may also be near orclose to each other without necessarily contacting each other. The exactdegree of proximity may in some cases depend on the specific context.

An initial overview of technology embodiments is provided below and thenspecific technology embodiments are described in further detail later.This initial summary is intended to aid readers in understanding thetechnology more quickly but is not intended to identify key features oressential features of the technology nor is it intended to limit thescope of the claimed subject matter.

Although typical sensors are generally effective for a given purpose,they often do not produce the same level of resolution in each degree offreedom. Additionally, obtaining measurement redundancy and/ormeasurements in multiple degrees of freedom can significantly increasesize, complexity, and cost, which can preclude using redundant ormultiple degree of freedom sensors in some applications. Thus, redundantsensors or multiple degree of freedom sensors can be more readilyutilized by maintaining size, complexity, and cost within practicallimits, such as those approximating single degree of freedom sensors.

Accordingly, a sensor is disclosed that can provide for redundancyand/or measurement in multiple degrees of freedom without significantlyincreasing size, complexity, or cost. In one aspect, the sensor can beadapted to measure any given quantity that can be determined using adisplacement measurement. The sensor can include a light component insupport of a first light source operable to direct a first beam oflight, and a second light source operable to direct a second beam oflight. The sensor can also include an imaging device positionedproximate the light component and operable to directly receive the firstbeam of light and the second beam of light and convert these intoelectric signals. The imaging device and the light component can bemovable relative to one another. The sensor can further include a lightlocation module configured to receive the electric signals and determinelocations of the first beam of light and the second beam of light on theimaging device. In addition, the sensor can include a position moduleconfigured to determine a relative position of the imaging device andthe light component based on the locations of the first beam of lightand the second beam of light on the imaging device.

In one aspect, a multi degree of freedom sensor is disclosed. The multidegree of freedom sensor can include a light component in support of afirst light source operable to direct a first beam of light, and asecond light source operable to direct a second beam of lightnon-parallel to the first beam of light. The multi degree of freedomsensor can also include an imaging device positioned proximate the lightcomponent and operable to directly receive the first beam of light andthe second beam of light and convert these into electric signals. Theimaging device and the light component can be movable relative to oneanother in at least two translational degrees of freedom and at leasttwo rotational degrees of freedom. The multi degree of freedom sensorcan further include a light location module configured to receive theelectric signals and determine locations of the first beam of light andthe second beam of light on the imaging device. Additionally, the multidegree of freedom sensor can include a position module configured todetermine a relative position of the imaging device and the lightcomponent based on the locations of the first beam of light and thesecond beam of light on the imaging device.

In another aspect, a multi degree of freedom sensor is disclosed. Themulti degree of freedom sensor can include a light component in supportof a plurality of light sources operable to direct beams of light. Themulti degree of freedom sensor can also include an imaging devicepositioned proximate the light component and operable to directlyreceive the beams of light and convert these into electric signals. Theimaging device and the light component can be movable relative to oneanother in a plurality of translational degrees of freedom and aplurality of rotational degrees of freedom. The multi degree of freedomsensor can further include a light location module configured to receivethe electric signals and determine locations of the beams of light onthe imaging device. Additionally, the multi degree of freedom sensor caninclude a position module configured to determine a relative position ofthe imaging device and the light component based on the locations of thebeams of light on the imaging device.

One embodiment of a sensor 100 is illustrated schematically in FIGS. 1and 2. The sensor 100 can comprise an imaging device 110. The imagingdevice 110 can comprise an image sensor 111, such as a pixel sensor,photo sensor, or any other suitable type of imager that can convertlight into electrical signals. In one aspect, the imaging device 110 cancomprise an active pixel sensor having an integrated circuit containingan array of pixel sensors, wherein each pixel contains a photodetectorand an active amplifier. Circuitry next to each photodetector canconvert the light energy to a voltage. Additional circuitry may beincluded to convert the voltage to digital data. One example of anactive pixel sensor is a complementary metal oxide semiconductor (CMOS)image sensor. In another aspect, the image device 110 can comprise acharge-coupled device (CCD) image sensor. In a CCD image sensor, pixelscan be represented by p-doped MOS capacitors. These capacitors arebiased above the threshold for inversion when light acquisition begins,allowing the conversion of incoming photons into electron charges at asemiconductor-oxide interface. The CCD is then used to read out thesecharges. Additional circuitry can convert the voltage into digitalinformation. The imaging device 110 can therefore include any suitabledevice or sensor that is operable to capture light and convert it intoelectrical signals, such as an imaging sensor typically found in digitalcameras, cell phones, web cams, etc.

The sensor 100 can also include a light component 120 in support of oneor more light sources 121, 122 operable to direct beams of light 123,124, respectively. The light source 121, 122 can comprises an LED, alaser, an organic LED, a field emission display element, asurface-conduction electron-emitter display unit, a quantum dot, a cellcontaining an electrically charged ionized gas, a fluorescent lamp, ahole through which light from a larger light source located external tothe plane of light emission can pass, and/or any other suitable lightsource. FIG. 3A illustrates a lens 227 operable with a light source 221to focus or direct light from the light source 221 into a suitable beamof light. FIG. 3B illustrates a collimator 328 operable with a lightsource 321 to “narrow” light from the light source 321 into a suitablebeam of light. It should be recognized that a lens and a collimator canbe used alone or in any combination with a light source to achieve asuitable beam of light.

The imaging device 110 can be positioned proximate the light component120 and operable to directly receive the beams of light 123, 124 andconvert these into electric signals. A light location module 130 can beconfigured to receive the electric signals and determine locations ofthe beams of light 123, 124 on the imaging device 110. For example,pixels of the imaging device 110 can be individually addressed such thatthe light intensity on each individual pixel may be known or determinedby the light location module 130.

The imaging device 110 and the light component 120 can be movablerelative to one another in one or more degrees of freedom. Thus, aposition module 140 can be configured to determine a relative positionof the imaging device 110 and the light component 120 based on thelocations of the beams of light 123, 124 on the imaging device 110. Inone aspect, the imaging device 110 and the light component 120 can becoupled 112 to one another in a manner that facilitates relativemovement. For example, the light component 120 can be “fixed” and theimaging device 110 can be supported about the light component 120 by astructure, device, or mechanism that can facilitate movement of theimaging device 110 relative to the light component 120. It should berecognized that in some embodiments the imaging device 110 can be“fixed.” The imaging device 110 and the light component 120 can beconstrained for relative movement only in one or more selected degreesof freedom, such as translation in the X axis or rotation about the Zaxis. Any suitable arrangement of the imaging device 110 and the lightcomponent 120 is contemplated that facilitates relative movement of theimaging device 110 and the light component 120 in one or more desireddegrees of freedom.

Such relative movement of the imaging device 110 and the light component120 can facilitate measurement of a relative movement, such as arelative displacement and/or a rotation. Accordingly, a sensor inaccordance with the present disclosure can be operable to measure orsense any quantity that can be based on, or that can be derived from, arelative movement, such as displacement, rotation, velocity,acceleration, etc. For example, a sensor as described herein canfunction as a position sensor, a strain gage, an accelerometer, a loadsensor, or any other type of sensor that can utilize a relative motionto mechanically and/or computationally provide a measurement of adesired type. In one aspect, therefore, the sensor 100 can also includea clock 150 to measure elapsed time associated with a relative movement,as may be useful for determining velocity, acceleration, or otherdynamic measurement quantities.

In addition, because the individual addresses of the pixels are known,the sensor 100 can be considered an “absolute” sensor. This attributeallows the sensor 100 to be powered off when not needed (i.e., toconserve energy) and powered on again to take a measurement or readingwithout needing to be initialized or otherwise calibrated to determinethe relative position of the imaging device 110 and the light component120.

The imaging device 110 can comprise a pixel array of any suitable size,dimension, aspect ratio, and/or pixel count. For example, the pixelarray can be a one-dimensional array or a two-dimensional array, such asan array of pixels arranged in rows and columns. In one aspect, a rangeof motion of the sensor can be limited by the size of the imagingdevice, although multiple imaging devices can be disposed adjacent toone another to provide a greater range of motion for the sensor. Inanother aspect, a range of motion of the sensor can be impacted by thelocation and/or size of the light sources. Thus, light sources can belocated and/or sized to accommodate the desired relative movementsbetween the light component and the imaging device. It should berecognized that a sensor in accordance with the present disclosure canalso produce substantially the same level of resolution in each degreeof freedom.

In one aspect, center locations of the beams of light 123, 124 on theimaging device 110 can be determined utilizing a statistical methodapplied to the locations of the beams of light 123, 124 on the imagingdevice 110. Such computations can be performed by the position module140. For example, each beam of light 123, 124 can be distributed acrossmany pixels on the imaging device 110 and can exhibit an intensitygradient that can be analyzed using statistical methods to determine thecenter of the beam.

In another aspect, the imaging device 110 can be monochromatic orchromatic and the light sources 121, 122 can produce any suitable colorof light, such as white, red, green, or blue. The color selectivity ofchromatic pixels to specific light beam wavelengths can be utilized toeffectively increase pixel populations, which can be used to determinethe location of the center of the beams without degradation from aneighboring light beam on the imaging device. For example, three lightsources (red, green, and blue) can be used in close proximity to oneanother with a chromatic imaging device in place of a single lightsource with a monochromatic imaging device to determine a relativemovement of the light component 120 and the imaging device 110 withoutinterference from one another. The chromatic imaging device can track orsense different color light beams separately, even though the lightbeams may overlap on the imaging device. Different parts of the imagingdevice corresponding to different colors can generate separate signalsthat can be used to determine the relative movement of the light sourceand the imaging device, such as by providing redundancy and/oradditional data points for computation.

Thus, in one aspect, the imaging device can comprise a color separationmechanism 160. Any suitable color separation mechanism can be used, suchas a Bayer sensor in which a color filter array passes red, green, orblue light to selected pixel sensors, a Foveon X3 sensor in which anarray of layered pixel sensors separate light via the inherentwavelength-dependent absorption property of silicon, such that everylocation senses all three color channels, or a 3CCD sensor that hasthree discrete image sensors, with the color separation done by adichroic prism.

FIGS. 4-7B, with continued reference to FIGS. 1 and 2, illustrate thesensor 100 undergoing relative movement of the imaging device 110 andthe light component 120. The light source 121 produces light beam 123that can be referred to generally as a “perpendicular” light beam, inthat the light beam 123 is perpendicular or substantially perpendicularto the imaging device 110 in a nominal relative orientation of theimaging device 110 and the light component 120. The light source 122produces light beam 124 that can be referred to generally as an “angled”light beam, in that the light beam 124 is at a non-perpendicular andnon-parallel angle to the imaging device 110 in a nominal relativeorientation of the imaging device 110 and the light component 120. Thelight sources 121, 122 can therefore be termed perpendicular and angledlight sources, respectively.

In general, a single light source can be used to determine relativemovement in two translational degrees of freedom. As shown in FIG. 4 forexample, the light source 121, which directs the light beam 123substantially perpendicular to the X and Y translational degrees offreedom, can be used to determine relative movement of the imagingdevice 110 and the light component 120 in these two translationaldegrees of freedom. In addition, the light source 122, which directs thelight beam 124 non-parallel to the light beam 123, can be used todetermine relative movement of the imaging device 110 and the lightcomponent 120 in the X and Y translational degrees of freedom. Movementby the light beams 123, 124 can trace paths 125 a, 126 a, respectively,along the imaging device 110 as the imaging device 110′ moves from aninitial position to the final position of the imaging device 110. Pixelsalong each of the paths 125 a, 126 a can be used to determine therelative motion of the imaging device 110 and the light component 120,such as by providing redundancy and/or additional data points forcomputation.

As shown in FIG. 5, and with further reference to FIGS. 1 and 2, theimaging device 110 and the light component 120 can be movable relativeto one another in a rotational degree of freedom, in this case about theZ axis.

Movement by the light beams 123, 124 can trace paths 125 b, 126 b,respectively, along the imaging device 110 as the imaging device 110′moves from an initial position to the final position of the imagingdevice 110. Pixels along the paths 125 b, 126 b of both light beams 123,124, respectively, can be used to determine the relative motion of theimaging device 110 and the light component 120, which in this case has acenter of rotation 101. As illustrated, the light beam 123 is directedsubstantially parallel to the axis of the rotational degree of freedomand the light beam 124 is non-parallel to the light beam 123. In otherwords, a perpendicular beam and an angled beam are used. It should berecognized, however, that relative movement in the translational androtational degrees of freedom shown in FIGS. 5 and 6 can be determinedwith two perpendicular beams or two angled beams.

FIG. 6 illustrates that the imaging device and the light component canbe movable relative to one another in a translational degree of freedom,in this case, along the Z axis. In other words, the perpendicular lightbeam 123 is directed substantially parallel to the axis of thetranslational degree of freedom and the angled light beam 124 isnon-parallel to the light beam 123, such that relative movement of theimaging device 110 and the light component 120 in the translationaldegree of freedom causes the light beam 123 and/or the light beam 124 tobe directed onto different locations of the imaging device 110. Forexample, as the imaging device 110 moves in direction 102 along the Zaxis toward the light component 120, the angled light beam 124 moves indirection 103 along the imaging device 110. This movement of the angledlight beam 124 can be used to determine the relative translationalmovement along the Z axis. In addition, the lack of movement of theperpendicular light beam 123 can also factor into a determination of therelative translational movement along the Z axis. It should berecognized, therefore, that a single angled beam of light can be used todetermine relative movement in three orthogonal translational degrees offreedom.

FIGS. 7A and 7B illustrate further use of the angled light beam 124 indetermining relative movement of the imaging device 110 and the lightcomponent 120 in a rotational degree of freedom, in this case about theX axis. Thus, the perpendicular light beam 123 is directed substantiallyperpendicular to the axis of the rotational degree of freedom. As shownin FIG. 7A, angled light beam 124 moves in direction 104 along theimaging device 110 and perpendicular light beam 123 moves in oppositedirection 105 along the imaging device 110. The difference in directionsas well as the relative locations of the light beams 123, 124 on theimaging device 110 and the angle 127 of the angled light beam 124 can beused to determine that the imaging device 110 rotated relative to thelight component 120 in direction 106 a about a center of rotation 107 a.In this case, both light beams 123, 124 are on the “same side” of thecenter of rotation 107 a.

As shown in FIG. 7B on the other hand, angled light beam 124 moves indirection 108 along the imaging device 110 and perpendicular light beam123 moves in the same direction 109 along the imaging device 110. Thesimilarity in directions as well as the relative locations of the lightbeams 123, 124 on the imaging device 110 and the angle 127 of the angledlight beam 124 can be used to determine that the imaging device 110rotated relative to the light component 120 in direction 106 b about acenter of rotation 107 b. In this case, both light beams 123, 124 are on“opposite sides” of the center of rotation 107 b. Thus, the movement anddirection of the angled beam 124 and the perpendicular beam 123 alongthe imaging device 110 can be used to determine the relative movement ofthe imaging device 110 and the light component 120 in a rotationaldegree of freedom that tends to move portions of the imaging device 110and the light component 120 toward one another, such as rotation aboutthe X axis.

It should be recognized that a sensor in accordance with the presentdisclosure can have multiple translational degrees of freedom and/ormultiple rotational degrees of freedom. Additional light sources, overthe two light sources 121, 122 of sensor 100, can reduce or eliminatesituations that can “trick” the sensor into incorrectly determining arelative movement, particularly when complex movements are compoundedinto multiple translational and rotational degrees of freedom. Anotherbenefit of additional light sources, in general, is improved resolutionof the sensor, in that there is more light movement across the imagingdevice and therefore more pixels to interrogate to obtain data can beutilized to determine the relative movement of the imaging device andthe light component. A further benefit of additional light sources, overtwo light sources, is simplified calculation algorithms.

Accordingly, FIG. 8 illustrates an embodiment of a sensor 400 that caneliminate potential computational ambiguities as well as improveresolution due to the number, placement, and orientation of the lightsources, particularly when undergoing relative movement in multipledegrees of freedom. For example, the sensor 400 can include fourperpendicular light sources 421 a-d and four angled light sources 422a-d. In one aspect, the angled light sources 422 a-d can be oriented todirect light beams 424 a-d in planes parallel to degree of freedom axes.For example, light beams 424 a, 424 b are in planes parallel to the Yaxis and light beams 424 c, 424 d are in planes parallel to the X axis.It should be recognized, however, that the angled light beams can beoriented in any direction, as illustrated by light beam 424 a′, which isoriented in some arbitrary direction.

The particular arrangement shown in the figure has the perpendicularlight sources 421 a-d located in a center portion of the light component420 and angled light sources 422 a-d located generally about a peripheryof the perpendicular light sources 421 a-d. Due to their nominalperpendicular orientation with respect to the imaging device 410, thelight beams generated by the perpendicular light sources 421 a-d willnot “sweep across” as much of the imaging device 410 as the light beams424 a-d of the angled light sources 422 a-d during movement that altersa relative position of the imaging device 410 and the light component inthe Z axis, such as Z axis translation, or rotation about the X and Yaxes. Light sources, such as the angled light sources 422 a-d, cantherefore be positioned and/or oriented to provide greater movementacross the imaging device 410 for relative movements of the imagingdevice 410 and the light component 420 in certain degrees of freedom,which can enhance the resolution of the sensor data. Thus, grouping theperpendicular light sources 421 a-d in a center portion and disposingthe angled light sources 422 a-d about a periphery of the perpendicularlight sources 421 a-d can be an efficient placement configuration formaximizing effective use of the imaging device area available with anincreased number of light sources 421 a-d, 422 a-d. In one aspect,colored light sources and a color separation mechanism can also beemployed to fit an increased number of light sources into a small areawithout degrading the performance of the sensor.

The number of light sources and the placement and orientation of thelight sources shown in the figure is merely illustrative of aconfiguration that can be used to ensure that no relative movement ofthe imaging device and light component can “trick” the sensor into afaulty or incorrect reading. It should be recognized therefore that anynumber of perpendicular or angled light sources can be used in anyrelative position or orientation to achieve a desired result, such asredundancy or level of resolution.

FIG. 9 illustrates another embodiment of a sensor 500 that can includemultiple light sources 510 a-c as well as multiple imaging devices 510a-f disposed adjacent to one another to provide continuous measurementover a larger range of motion that may available using only a singleimaging device. For example, the sensor 500 can include any of thefeatures and elements described hereinabove, such as a light component520 in support of the light sources 521 a-c (which may be perpendicularand/or angled) that direct light beams 523 a-c, respectively, toward oneor more of the imaging devices 510 a-f at a given time. As shown, theimaging devices 510 a-f are arranged in a staggered configuration with aregion 514 in between imaging devices where no image sensor is present,such as at an interface between adjacent imaging devices. A light beam523 a may terminate 529 a in the region 514 between adjacent imagingdevices 510 a, 510 b, in which case the light beam 523 a will notcontribute to the position determining functionality of the sensor 500.However, in this case, light beams 523 b, 523 c can terminate 529 b, 529c on imaging devices 510 b, 510 e, respectively, to contribute to theposition determining functionality of the sensor 500 even when the lightbeam 523 a cannot. In other words, the other imaging devices 510 b, 510e still receiving light beams 523 b, 523 c, respectively, can compensatefor the loss of signal from any given light source, such as 521 a. Inone aspect, the number and/or arrangement of imaging devices and/orlight sources can be configured to ensure that at least one light sourcewill terminate on an imaging device throughout a desired range of motionof the sensor and in any degree of freedom of the sensor Thus, in thisway, multiple light sources can be used to ensure that the sensor 500 isoperable to determine relative position of the light component 520 andthe imaging devices 510 a-f even when a light source is directing a beamof light to an area that is without an image sensor.

With reference to FIGS. 10A and 10B, illustrated are two additionalsensors in accordance with the present disclosure. For example, FIG. 10Aillustrates a sensor 600 having an elastic member 670, 671 coupled tothe imaging device 610 and the light component 620 to facilitaterelative movement of the imaging device 610 and the light component 620.The elastic member 670, 671 can establish a nominal relative positionfor the imaging device 610 and the light component 620 and canfacilitate relative movement of the imaging device 610 and the lightcomponent 620 in any suitable degree of freedom. The elastic member 670,671 can comprise a spring, which can be configured as any suitable metalspring or as an elastomeric spring. Thus, in one aspect, the elasticmember 670, 671 can act as a polymer suspension system for the imagingdevice 610 and the light component 620.

In one aspect, the elastic member 670, 671 can be disposed outboard ofthe light sources 621, 622. In another aspect, the elastic member cancomprise a transparent layer disposed between the imaging device 610 andthe light component 620. In one embodiment, the elastic member cancomprise a silicone layer that acts as a separator between the imagingdevice 610 and the light component 620, which may provide a lowdisplacement and high resolution sensor. In one aspect, the range ofmotion for the sensor 600 can be limited by the size of the imagingdevice 610 and the type of suspension or separation structure, which candepend on the magnitude of the desired range of motion and/or theapplication of the particular sensor.

For example, one application for the sensor 600 can be as a strain gage.In this case, the imaging device 610 can be anchored to a surface 613 atlocation 614 and the light component can be anchored to the surface 613at location 615. As the surface 613 experiences strain, the imagingdevice 610 and the light component 620 will move relative to oneanother, which movement can serve to facilitate measurement of thestrain in one or more degrees of freedom.

FIG. 10B illustrates another example of a sensor 700 having a mass 780associated with the light component 720, which can enable the sensor 700to measure acceleration and/or function as a navigation aid. The mass780 and the light component 720 can be supported by an elastic member770, such as a spring, to facilitate relative movement of the imagingdevice 710 and the light component 720 in one or more degrees offreedom. In one aspect, the elastic member 770 can be coupled to asupport structure 790, which can be coupled to the imaging device 710.Although the light component 720 is shown in the figure as beingassociated with the mass 780 and suspended by the elastic member 770, itshould be recognized that the imaging device 710 can be associated withthe mass 780 and suspended by the elastic member 770.

In another example of a sensor (not shown), a whisker can be coupled toan imaging device or a light component and placed in a flow field todetermine boundary layer thickness. In yet another example of a sensor(not shown), an imaging sensor and a light component can be configuredfor continuous relative rotation to measure rotary position.

In accordance with one embodiment of the present invention, a method forfacilitating a displacement measurement is disclosed. The method cancomprise providing a light component in support of a first light sourceoperable to direct a first beam of light, and a second light sourceoperable to direct a second beam of light. The method can also compriseproviding an imaging device positioned proximate to the light componentand operable to directly receive the first beam of light and the secondbeam of light and convert these into electric signals. The method canfurther comprise providing a light location module configured to receivethe electric signals and determine locations of the first beam of lightand the second beam of light on the imaging device. The method can stillfurther comprise providing a position module configured to determine arelative position of the imaging device and the light component based onthe locations of the first beam of light and the second beam of light onthe imaging device. Additionally, the method can comprise facilitatingrelative movement of the imaging device and the light component. It isnoted that no specific order is required in this method, thoughgenerally in one embodiment, these method steps can be carried outsequentially.

In one aspect of the method, the second beam of light is non-parallel tothe first beam of light. In another aspect of the method, facilitatingrelative movement of the imaging device and the light componentcomprises facilitating relative movement in at least one of atranslational degree of freedom and a rotational degree of freedom.

It is to be understood that the embodiments of the invention disclosedare not limited to the particular structures, process steps, ormaterials disclosed herein, but are extended to equivalents thereof aswould be recognized by those ordinarily skilled in the relevant arts. Itshould also be understood that terminology employed herein is used forthe purpose of describing particular embodiments only and is notintended to be limiting.

Reference throughout this specification to “one embodiment” or “anembodiment” means that a particular feature, structure, orcharacteristic described in connection with the embodiment is includedin at least one embodiment of the present invention. Thus, appearancesof the phrases “in one embodiment” or “in an embodiment” in variousplaces throughout this specification are not necessarily all referringto the same embodiment.

As used herein, a plurality of items, structural elements, compositionalelements, and/or materials may be presented in a common list forconvenience. However, these lists should be construed as though eachmember of the list is individually identified as a separate and uniquemember. Thus, no individual member of such list should be construed as ade facto equivalent of any other member of the same list solely based ontheir presentation in a common group without indications to thecontrary. In addition, various embodiments and example of the presentinvention may be referred to herein along with alternatives for thevarious components thereof. It is understood that such embodiments,examples, and alternatives are not to be construed as de factoequivalents of one another, but are to be considered as separate andautonomous representations of the present invention.

Furthermore, the described features, structures, or characteristics maybe combined in any suitable manner in one or more embodiments. In thedescription, numerous specific details are provided, such as examples oflengths, widths, shapes, etc., to provide a thorough understanding ofembodiments of the invention. One skilled in the relevant art willrecognize, however, that the invention can be practiced without one ormore of the specific details, or with other methods, components,materials, etc. In other instances, well-known structures, materials, oroperations are not shown or described in detail to avoid obscuringaspects of the invention.

While the foregoing examples are illustrative of the principles of thepresent invention in one or more particular applications, it will beapparent to those of ordinary skill in the art that numerousmodifications in form, usage and details of implementation can be madewithout the exercise of inventive faculty, and without departing fromthe principles and concepts of the invention. Accordingly, it is notintended that the invention be limited, except as by the claims setforth below.

The invention claimed is:
 1. A sensor, comprising: a first light sourcethat generates a first beam of light; a second light source thatgenerates a second beam of light, wherein the first light source and thesecond light source are supported by a light support structure; animager that receives the first beam of light and the second beam oflight, wherein the imager and the light support structure are movablerelative to one another; and one or more elastic members that connectthe light support structure to the imager, wherein the one or moreelastic members are operable to facilitate relative movement of theimager and the light support structure; wherein the sensor: determineslocations of the first beam of light and the second beam of light on theimager, and determines a relative position of the imager and the lightsupport structure based on the locations of the first beam of light andthe second beam of light.
 2. The sensor according to claim 1, whereinthe second beam of light is non-parallel to the first beam of light. 3.The sensor according to claim 1, wherein the first light source is amonochromatic light source and the first beam of light is a first color,wherein the second light source is a monochromatic light source and thesecond beam of light is a second color; and wherein the imager includes:a first monochromatic detector that receives light of the first colorand converts the light of the first color into a first electricalsignal, and a second monochromatic detector that receives light of thesecond color and converts the light of the second color into a secondelectrical signal.
 4. The sensor according to claim 1, wherein the firstlight source is a chromatic light source and the second light source isa chromatic light source; and wherein the imager includes: a colorseparation mechanism that separates the first beam of light and thesecond beam of light into a beam of light of a first color and a beam oflight of a second color, a first monochromatic detector receives thebeam of light of the first color and converts the beam of light of thefirst color into a first electrical signal, and a second monochromaticdetector that receives the beam of light of the second color andconverts the beam of light of the second color into a second electricalsignal.
 5. The sensor according to claim 1, wherein the sensor furtherdetermines the relative movement of the light support structure and theimager in multiple degrees of freedom.
 6. The sensor according to claim1, wherein the one or more elastic members form a transparent layerbetween the imager and the light support structure.
 7. The sensoraccording to claim 1, wherein the light support structure ismechanically coupled to an object to be sensed; and the sensor furthercalculates a strain on a surface of the object in one or more degrees offreedom based on the relative position of the imager and the lightsupport structure.
 8. The sensor according to claim 1, wherein the lightsupport structure further supports a known mass; and the sensor furtherdetermines acceleration based on the known mass and the relativeposition of the imager and the light support structure.
 9. The sensoraccording to claim 1, further comprising: one or more additional lightsources that each generate a respective beam of light, wherein the oneor more additional light sources; and wherein the imager receives eachrespective beam of light, and the sensor further determines the relativeposition of the imager and the light support structure based onlocations of each respective beam of light determined by the sensor. 10.The sensor according to claim 1, wherein the imager is a chromaticimaging device that senses different color light beams separately.